Harvesting yeast - long term

[mortong]

I have a question about harvesting and re-using yeast.

I've heard you're safe to about six batches before mutations get out of hand and your beers develop a "house" flavor.

Is this necessarily a bad thing. I'm thinking of breweries that have the same "house" flavor in all their beers from their yeast - Henry's when they were still a micro comes to mind (yes, I'm still bitter about this - that was my first-love and it broke my heart to see the original brewery torn down to make a parking lot :confused: ).

I can see how this could be hit-or-miss as far as how pleasing the flavors are, but is contamination also an issue?

I think it might be fun to try something like this - allow my yeast to develop on its own to see where it goes.

Any thoughts, anyone?

Geoff

[brewmonkey]

In good conditions you can continue to harvest yeast as long as you take care of it.

Homebrewers should not go more then 2-3 batches.

The house flavors you refer to generally come from contamination and as they develop, you will build a tolerance to them and before you know it you are the only one who will drink your beer.

The problem with harvesting and repitching in continued generations is the mutation that occurs to the yeast. As the gens grow the yeast becomes weaker and will stop performing to the standard you would expect.

Some noticed problem would be failure to reach attenuation, failure to flocculate or in some cases autolysis kicks in and toasts the batch.

Harvesting and repitching is a great tool for brewers, especially when you have a strain you are really digging. Just be careful and keep your eyes on it. House flavors are not always a good thing!

[Beerconnoisseur]

If you find a house strain that you happen to love, is there anything that can be done to preserve the strain, mutation/contamination and all?

With all the advances in biochemistry, and sequencing the human genome, it would seem to be a much easier task to tweak a yeast culture to do your nefarious bidding, say, by producing passion fruit esters for a "Spring Break Ale." :D

Or is this too much to ask for, even for a well-stocked lab?

[mortong]

I actually thought of this topic when reading some of M. Jackson's books - he talks about farmer/homebrew families that have been doing it for centuries, and have the same strain still living in their wooden stirring stick.

After Brewmonkey's response I started wondering how over the generations, their beer wasn't drinkable only to them -- and were highly praised by Jackson. The only answer I can think of is that those family yeasts were of the same strains (starting as wild yeast) that we eventually domesticated and produced tastes that we now consider standard in our beers.

But that still leaves a few questions - how do those centuries-old yeast strains kept in the family stay stable, and is it possible for us to do it?

Geoff

[brewmonkey]

They are able to do it by slanting it out and reculturing it. They are not simply grabbing some from the crop and repitching it.

If you have the lab and the equipment to do it, you will never have to buy another vial of yeast again. I know several brewers who do this and keep several house strains in their inventory for the different beers they produce.

If you were to continue to just repitch the yeast without slanting it you would experience the problems I mentioned in the other post.

The lab environment is exactly how the yeast companies like White Labs and Wyeast grow their yeast as well. They have an original culture that they use, and the grow other from that. When they find that their product is no longer meeting the standard they return and take a colony from the original culture and prop it up.

So, like i said. Many brewhouses are using the original strain but it has been recultured they are not just simply harvesting and repitching.

Hope this makes sense as it is early and I am waiting for the damned coffee pot to finish!

[Fast_Eddy]

There's a good article in this months BYO about how Sierra Nevada does exactly what Brewmonkey is talking about.

I was cruising the Siebel Institute site the other day and noticed that they will maintain a strain for you for something like $75 a year with some initial upfront fee. So, Beerconnoisseur, if you come up with some incredible yeast I guess you could have them keep a slant or two for you.

[sallad]

i've been thinking of using sierra nevada as my slant... in otherwords, when ever i want to brew a pale ale or similar, culture the yeast from a bottle of SNPA! with this group of experts, i'm sure we could come up with a commercial b.c.a. that has yeast suitable for nearly every style! i saw a website somewhere that tried to do exactly that..... have to look in the archives, pretty sure its posted on here somewhere.

[cyanide]

Here's an interesting article I came across here:
http://beernotes.com/midwest/articles/000253.html

It's about taking one yeast strain and splitting it up into six bottles. The nice part is, that you will be using yeast in each batch 'fresh' and not after it was used in the beer, so the risk of infection drops dramatically. I'm thinking of buying a lager yeast soon for some winter brewing and trying it during the cold months :)

[toneyc]

Yup, I've been doing the parallel yeast culture thing for a few months now. It works great and saves a bundle. I picked three kinds of beer that I liked to make, or that the yeast used was versatile and parallel'd them. I've got an American Ale, an English Ale, and a Kolsch Ale yeast all bottled and waiting for a brew session.

:)
Toney.